Dual plenum for air distribution

ABSTRACT

The dual plenum for air distribution comprises a first chamber (1) and a second chamber (2) sharing at least one common wall (14), an air inlet (3) only in the first chamber communicated to an air supply source (8) by a pressurized air supply conduit (9), an air passage regulating device (7) in the common wall (14) selectively communicating the second chamber to the first chamber in response to an air pressure level in the first chamber, a first air outlet (10) in the first chamber and a second air outlet (11) in the second chamber through which pressurized air is evacuated from the first and second chambers, respectively, to an enclosure. The first and second air outlets have respective first and second diffusers (12, 13) which provide respective horizontal first and second air passage areas (S1, S2) and which direct air within an enclosure in general of a building.

TECHNICAL FIELD

The present invention relates to a dual plenum useful in the field ofair conditioning ventilation and distribution systems, particularly todistribution systems for variable pressurized air volumes.

STATE OF THE ART

Air conditioning flow regulation and control systems are known in thestate of the art in which pressurized air from an air supply sourceaccesses a plenum from where it is distributed to an enclosure, such asa room, through a ceiling diffuser grating having a constant air passagearea.

The thermal load within an enclosure such as a room is highly variabledue, for example, to room temperature, the number of persons staying inthe enclosure, the kind of work they do, the number of apparatuses theyuse, the heat emissions that the apparatuses produce, etc. The known airconditioning flow regulation and control systems are designed to adaptthemselves to the changes in the room thermal load by automaticallyincreasing or decreasing an air flow rate which is supplied from the airsupply source to the plenum and which is evacuated from the plenum tothe room through the ceiling diffuser grating having the constant airpassage area. As a result, the speed of the air flow that is distributedto the enclosure from the plenum increases under high thermal loadconditions, and a high speed of the air flowing from the ceilingdiffuser grating can be uncomfortable for people in the room.

Document U.S. Pat. No. 6,986,708 B2 discloses a dual plenum for airdistribution which is divided into two spaces with a transversepartition, namely an air supply plenum which acts to supply air from anair handling unit to a room and an air return plenum which operates forreturning room air to the air handling unit, with the air supply plenumbeing arranged below the air return plenum. A terminal unit having acontrollable damper blade is applied to a diffuser to permit the unit tobe convertible between a constant volume unit and a variable volumeunit. A thermostat generates signals that open and close the damperblade at determined intervals. However, this dual plenum is not intendedfor nor does it allow regulating the speed of the air flow that isdistributed to the enclosure from the two plenums by varying an outletair passage area and without the use of mechanically operated elements.

Document U.S. Pat. No. 3,929,280 A discloses a terminal air outletdevice for use at a discharge from a building air distribution systemincluding a plenum for air distribution comprising a housing; a chamberdefined within the housing; an inlet leading into the chamber and beingadapted for connection to an air supply source; a first air outlet fromthe chamber through which air is adapted to be discharged in a firstfixed direction; a second air outlet from the chamber through which airis adapted to be discharged in a second fixed direction different fromthe first one, which is substantially at right angles to the firstdirection; and control means for regulating air discharge through thefirst and second outlets. The first direction is substantially vertical,and the second direction is substantially horizontal. Heated air isdischarged in the first vertical direction, and cool air in the secondhorizontal direction. However, this plenum is not intended for nor doesit allow discharging air to an enclosure from the two air outlets inresponse to the fluctuations of thermal load within the enclosure, inmutually parallel directions, or in different directions that can beselected and oriented because the two adjacent chambers do not share anair outlet.

Document U.S. Pat. No. 4,259,898 A discloses a dual plenum having allthe features of the preamble of claim 1.

Accordingly the dual plenum of U.S. Pat. No. 4,259,898 A comprises afirst chamber having a first air inlet and a first air outlet, a secondchamber having a second air inlet and a second air outlet, and anair-feed device configured to introduce pressurized air from an airsupply source to the first chamber through the first air inlet and tothe second chamber through the second air inlet. First and secondchamber in this dual plenum share an air supply conduit and also sharean air outlet having diffusers allowing to direct the pressurized air tocommon or different selectable/orientable directions. A regulatingdamper is swingable suspended in the second air inlet and subjected tothe action of its own weight so that when the air supply source deliversa relatively small volume of air the regulating damper remains in aclosed position and the supplied air flows only through the first airinlet and the first air outlet. If the air supply source delivers arelatively large volume of air the regulating damper is swung and thesupplied air flows both through the first and second air inlets andfirst and second air outlets. However, in this dual plenum there is noan air passage regulating device selectively communicating the secondchamber to the first chamber and therefore a given flow rate ofpressurized air is not shunt from the first chamber to the secondchamber in response to an air pressure level in the first chamber inorder to cause a decrease in the speed of the air discharged from thefirst air outlet when a relatively large volume of air is delivered tothe plenum.

Therefore, new plenums for air distribution are required which, by meansof the variability of the outlet air passage area for diffusing air fromthe plenum to an enclosure, allow maintaining the output speed of theair as constant as possible in different flow rate conditions, thusimproving comfort and energy efficiency in the enclosures, rooms orpremises to be air conditioned.

DISCLOSURE OF THE INVENTION

For that purpose, the present invention provides a dual plenum for airdistribution comprising, as is already known for example from the citeddocument U.S. Pat. No. 4,259,898 A, a first chamber and a second chambersharing at least one common wall, and further sharing an air outlethaving diffusers in an air passage area configured to direct air withinan enclosure in general of a building. The dual plenum is connected toan air-feed device configured to selectively introduce pressurized airfrom an air supply source to the first chamber or to both the firstchamber and the second chamber in response to a supplied pressurized airflow rate, wherein the first chamber has a first air outlet throughwhich pressurized air is evacuated from the first chamber to anenclosure, and the second chamber has a second air outlet through whichpressurized air is evacuated from the second chamber to the enclosure,and wherein the first air outlet has first diffusers which provide ahorizontal first air passage area and which are configured to direct airin a downwards direction, and the second air outlet has second diffuserswhich provide a horizontal second air passage area and which areconfigured to direct air in the same downwards direction than the firstdiffusers or in different directions, so that the air flow that comesout from the double plenum through the shared outlet can be directed asdesired by using the first and second diffusers On the other hand, thetwo diffusers can be the same or different

Unlike the prior art, the air-feed device of the dual plenum of thepresent invention comprises an air inlet connected only to the firstchamber, a pressurized air supply conduit connected to the air supplysource and to the air inlet, and an air passage regulating device in thecommon wall, wherein the air passage regulating device is configured toselectively communicate the second chamber to the first chamber inresponse to an air pressure level in the first chamber caused by thesupplied pressurized air flow rate.

According to a preferred embodiment of this invention the common wallincluding the air passage regulating device is adjacent to a region ofthe first chamber directly connected to the first surface area of theair outlet without interposed constrictions, i.e. the air passage is farfrom the air inlet of the air supply conduit.

Thus, when the air pressure level in the first chamber is relativelylow, the air passage regulating device completely or almost completelyprevents an air communication between the first chamber and the secondchamber so that all or almost all the supplied pressurized air isdischarged through the first air outlet, the first air passage area ofwhich is selected to determine a relatively low air output speed.However, when the air pressure level in the first chamber is relativelyhigh, the air passage regulating device allows an air communicationbetween the first chamber and the second chamber so that a given flowrate of pressurized air is shunt from the first chamber to the secondchamber and the supplied pressurized air is discharged through both thefirst and second air outlets, the first and second air passage areas ofwhich add together to keep the air output speed at a relatively lowlevel.

In one embodiment, the air passage regulating device comprises one ormore communication openings in the common wall. These one or morecommunication openings are sized so that they provide a third airpassage, and a ratio of the third air passage area to the first airpassage area is selected to allow a given flow rate of pressurized airto be shunt from the first chamber to the second chamber in response tothe air pressure level in the first chamber.

The one or more communication openings are permanently open, so thatwhen the air pressure in the first chamber is relatively low, the airwill be diffused primarily through the first outlet air passage area andonly to a small extent through the second outlet air passage area. Butwhen the air pressure in the first chamber is relatively high, the airwill be diffused through both the first and second outlet passage areas.

In another embodiment, the air passage regulating device comprises aone-way valve device associated to a communication opening in the commonwall. The one-way valve device is configured to open in response to apressure value inside the first chamber above a specific threshold valuethereby allowing a given flow rate of pressurized air to be shunt fromthe first chamber to the second chamber. The one-way valve device allowsthe passage of the pressurized air in one direction and prevents it inthe opposite direction.

For example, the one-way valve device may be calibrated to open aspecific section of the communication opening depending on the higher orlower pressure difference between the first chamber and the secondchamber. If the one-way valve device is more open, the air flow would bediffused through the first air passage area of the first chamber andthrough the second air passage area of the second chamber outlet. In theevent that the one-way valve device is more closed, the air would bediffused primarily through the first air passage area and only to asmall extent through the second air passage area.

In the event that the one-way valve device is completely closed, airflow is not allowed to pass from the first chamber to the secondchamber, so that air cannot be diffused through the second outlet airpassage area and the entire air flow is diffused through the first airpassage area.

In one embodiment, the mentioned one-way valve device is comprised of asheet fixed at one of its ends to a wall common to the first and secondchambers and adjacent to the communication opening, with the capacity topivot with respect to the fixing and block the mentioned communicationopening to a greater or lesser degree, allowing a larger or smalleramount of air to pass through the communication opening. This sheet canbe a flexible sheet which deforms in response to external forces withrespect to the sheet, such as air pressure for example, and when flexingthe flexible sheet frees the communication opening between the chambers.

Alternatively, the sheet can be a rigid sheet, in which case the fixingcomprises a hinge at an edge of the sheet. The rigid sheet has thecapacity to pivot to open the communication opening to a greater orlesser degree in response to a pressure exerted on the rigid sheet. Inone embodiment, the communication opening is located in a verticalsection of the common wall, the hinge is located over the communicationopening, and the rigid sheet is biased to a closed position blocking thecommunication opening by the action of its own weight. In anotherembodiment, the communication opening is located in any wall common tothe first and second chambers, the hinge is attached to the common wallin a place adjacent to the communication opening, and the rigid sheet isbiased to the closed position blocking the communication opening by anelastic element.

Alternatively the one-way valve device can be, for example, anautomatically actuated mechanical valve device with which thecirculation of pressurized air through the communication opening can bestarted, stopped, or regulated by means of a movable part whichpartially opens, closes, or obstructs one or more orifices or conduitsassociated to the communication opening in cooperation with one or morepressure sensors and an electronic control device.

The first and second chambers of the dual plenum can be arrangedaccording to several configurations. In an embodiment, the common wallis a vertical cylindrical or prismatic wall surrounded by a cylindricalor prismatic side outer wall, and the second chamber is surrounded bythe first chamber. The first chamber is delimited by the common wall,the side outer wall, a first top wall, and a first bottom wall in whichthe first air outlet and the first diffusers are located. The secondchamber is delimited by the common wall, a second top wall, and a secondbottom wall in which the second air outlet and the second diffusers arelocated. The air inlet is located in the side outer wall or in the firsttop wall.

However, while other shapes of the common wall, for example frustumconical or similar are considered suitable),

In this embodiment, the first top wall has a perimetral edge connectedto the side outer wall and an aperture with an inner edge connected tothe common wall, and the second top wall has a perimetral edge connectedto the common wall, whereby the second chamber is surrounded by thefirst chamber, or alternatively the first top wall has a perimetral edgeconnected to the side outer wall, the second top wall has a perimetraledge connected to the common wall, whereby the second chamber issurrounded by the first chamber and a section of the first chamberextends between the first top wall and the second top wall.

In another embodiment, the common wall is also a vertical cylindrical orprismatic wall surrounded by a cylindrical or prismatic side outer wall,but the first chamber is surrounded by the second chamber. The firstchamber is delimited by the common wall, a first top wall, and a firstbottom wall in which the first air outlet and the first diffusers arelocated. The second chamber is delimited by the common wall, theprismatic side outer wall, a second top wall, and a second bottom wallin which the second air outlet and the second diffusers are located. Theair inlet is located in the common wall and the pressurized air supplyconduit communicates with the air inlet of the first chamber goingthrough the second chamber, or alternatively the air inlet is located inthe first top wall.

In this embodiment, the first top wall has a perimetral edge connectedto the common wall, and the second top wall has a perimetral edgeconnected to the side outer wall and an aperture with an inner edgeconnected to the common wall, whereby the first chamber is surrounded bythe second chamber, or alternatively the first top wall has a perimetraledge connected to the common wall, and the second top wall has aperimetral edge connected to the side outer wall, whereby the firstchamber is surrounded by the second chamber and a section of the secondchamber extends between the first top wall and the second top wall.

Preferably, in the embodiment where the second chamber is surrounded bythe first chamber, the one or more communication openings of the airpassage regulating device are formed in a region of the common wallfacing a portion of the side outer wall opposite the air inlet, and inthe embodiment where the first chamber is surrounded by the secondchamber, the one or more communication openings of the air passageregulating device are formed in a region of the common wall opposite theair inlet.

In a further embodiment the common wall is a vertical partition wallwhich is connected to the inside of a vertical cylindrical or prismaticside outer wall so that the first chamber and the second chamber arearranged adjacent side by side. In this case, the first chamber isdelimited by the common wall, a first portion of the side outer wall, afirst top wall, and a first bottom wall in which the first air outletand the first diffusers are located, and the second chamber is delimitedby the common wall, a second portion of the side outer wall, a secondtop wall and a second bottom wall in which the second air outlet and thesecond diffusers are located.

The air inlet can be located either in the first portion of the sideouter wall, or in the common wall, or in the first top wall. If the airinlet is located in the common wall, then the pressurized air supplyconduit communicates with the air inlet of the first chamber goingthrough the second chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other advantages and features will be betterunderstood based on the following detailed description of severalembodiments with reference to the attached drawings which are to betaken by way of non-limiting illustration, in which:

FIG. 1 is a vertical cross-section view of a dual plenum for airdistribution according to a first embodiment of the present invention,taken by the plane I-I of FIG. 2.

FIG. 2 is a horizontal cross-section view taken by the plane II-II ofFIG. 1.

FIG. 3 is a bottom view of the dual plenum of FIG. 1.

FIG. 4 is an isometric view of the dual plenum of FIG. 1 showing abottom side thereof from where diffusers have been removed for clarity;

FIG. 5 is an isometric view of a dual plenum according to a secondembodiment of the present invention, showing a bottom side thereof fromwhere diffusers have been removed for clarity;

FIG. 6 is a bottom view of a dual plenum according to a third embodimentof the present invention;

FIG. 7 is a vertical cross-section view of a dual plenum for airdistribution according to a fourth embodiment of the present invention,taken by the plane VII-VII of FIG. 8.

FIG. 8 is a horizontal cross-section view taken by the plane VIII-VIIIof FIG. 7.

FIG. 9 is a vertical cross-section view of a dual plenum for airdistribution according to a fifth embodiment of the present invention;

FIG. 10 is a vertical cross-section view of a dual plenum for airdistribution according to a sixth embodiment of the present invention;

FIG. 11 is a vertical cross-section view of a dual plenum for airdistribution according to a seventh embodiment of the present invention;

FIGS. 12 and 13 are vertical cross-section views of a dual plenum forair distribution according to an eighth embodiment of the presentinvention, showing a one-way valve device in a closed position and anopen position, respectively;

FIG. 14 is a vertical cross-section view of a dual plenum for airdistribution according to a ninth embodiment of the present invention;

FIGS. 15 and 16 are vertical cross-section views of a dual plenum forair distribution according to a tenth embodiment of the presentinvention, showing a one-way valve device in a closed position and anopen position, respectively; and

FIG. 17 is a vertical cross-section view of a dual plenum for airdistribution according to an eleventh embodiment of the presentinvention.

DETAILED DESCRIPTION OF SEVERAL EMBODIMENTS

The attached drawings show non-limiting illustrative embodiments of adual plenum for air distribution of the present invention, which isuseful in general as a ceiling air outlet, although it can provideequally horizontal flows from a wall or with a certain inclination,maintaining the principles of the invention, for an air conditioningventilation and distribution system.

It will be understood that the different parts constituting theinvention described in one embodiment can be freely combined with theparts described in other different embodiments, even though thecombination has not been explicitly described, provided that this is notdetrimental to the combination.

In the following drawings, a chamber the pressurized air supply conduitaccesses will be understood to mean a first chamber 1, and a chamberwhich communicates with the first chamber through one or morecommunication openings will be understood to mean a second chamber 2.

FIGS. 1 to 4 show a dual plenum according to a first embodimentcomprising a first chamber 1 and a second chamber 2 sharing a commonwall 14 which has the shape of a vertical quadrangular prismatic wall.The common wall 14 is surrounded by a quadrangular prismatic side outerwall 15. The first chamber 1 is delimited by the common wall 14, theside outer wall 15, a first top wall 16, and a first bottom wall, andthe second chamber 2 is delimited by the common wall 14, a second topwall 17, and a second bottom wall, so that the second chamber 2 issurrounded by the first chamber 1.

An air inlet 3 is located in the side outer wall 15. Alternatively, theair inlet 3 could be located in the first top wall 16. A pressurized airsupply conduit 9 is connected to an air supply source 8 and to the airinlet 3, so that pressurized air from the air supply source 8 isintroduced to the first chamber 1. An air passage regulating device 7 islocated in the common wall 14. The air passage regulating device 7comprises a communication opening configured to selectively communicatethe second chamber 2 to the first chamber 1 in response to an airpressure level in the first chamber 1 caused by a pressurized air flowrate supplied from the air supply source 8. The communication opening ofthe air passage regulating device 7 is formed in a region of the commonwall 14 facing a portion of the side outer wall 15 opposite the airinlet 3 in this embodiment

Thus, the air supply source 8, the pressurized air supply conduit 9, theair inlet 3, and the air passage regulating device 7 constitute anair-feed device configured to selectively introduce pressurized air tothe first chamber 1 or to both the first chamber and the second chamber2 in response to a supplied pressurized air flow rate.

A first air outlet 10 provided with first diffusers 12 is located in thefirst bottom wall of the first chamber 1, and a second air outlet 11provided with second diffusers 13 is located in the second bottom wallof the second chamber 2. Pressurized air is evacuated from the first andsecond chambers 1, 2 to an enclosure through the respective first andsecond air outlets 10, 11. The first and second diffusers 12, 13 areconfigured to direct air in one and the same downwards direction or indifferent directions, given the adjustable condition of the diffusers,for example of the grid type, according to the needs of the room orenclosure whose thermal load is to be controlled The first air outlet 10and the corresponding first diffusers 12 provide a first air passagearea S1 in a horizontal plane, and the second air outlet 11 and thecorresponding second diffusers 13 provide a second air passage area S2in a horizontal plane.

The communication opening constituting the air passage regulating device7 between the first and second chambers 1, 2 provides a third airpassage area S3. The ratio of the third air passage area S3 to the firstair passage area S1 is selected to allow a given flow rate ofpressurized air to be shunt from the first chamber 1 to the secondchamber 2 in response to the air pressure level in the first chamber 1.The higher is the air pressure level in the first chamber 1 the greateris the flow rate of pressurized air that is shunt from the first chamber1 to the second chamber 2.

Thus, the air flow rate entering the second chamber 2 through the thirdair passage area S3 increases and decreases with the rise and fall ofthe pressure in the first chamber 1, and the first and second airpassage areas S1, S2 of the first and second air outlets 10, 11 of thefirst and second chambers 1, 2 add together as convenient at any time tokeep the air output speed at a relatively constant level.

The first top wall 16 has a perimetral edge connected to the side outerwall 15 and an inner edge connected to the common wall 14 and the secondtop wall 17 has a perimetral edge connected to the common wall 14. Ascan be seen in FIG. 1, the first and second top walls 16, 17 are flushin a horizontal plane and can optionally be made of a single element,and the first and second diffusers 12, 13 are flush in anotherhorizontal plane and can optionally be made of a single element.Alternatively, the first and second top walls 16, 17 could be staggeredon different levels and the first and second diffusers 12, 13 could alsobe staggered on different horizontal levels. As can be seen in FIG. 3,the first and second diffusers 12, 13 have a different design.Alternatively, the first and second diffusers 12, 13 could be of thesame type o be a single diffuser, but in where the wall 14 they sharedetermines that they can operate as two distinct, separate diffusers.

FIG. 5 shows a dual plenum according to a second embodiment whichdiffers from the first embodiment (FIGS. 1 to 4) in that the common wall14 is a cylindrical wall instead of a quadrangular prismatic wall, andthe air passage regulating device 7 comprises a plurality of smallercommunication openings instead of a single greater communicationopening. The smaller communication openings provide all together thethird air passage area S3.

FIG. 6 shows a dual plenum according to a third embodiment which differsfrom the second embodiment (FIG. 5) in that the outer side wall 15 is acylindrical wall instead of a quadrangular prismatic wall. Here, thefirst and second diffusers 12, 13 are joined into a common diffuserspanning over the first and second outlets 10, 11.

FIGS. 7 and 8 show a dual plenum according to a fourth embodiment whichdiffers from the first embodiment (FIGS. 1 to 4) in that the firstchamber 1 is delimited by the common wall 14, the first top wall 16, andthe first bottom wall in which the first air outlet 10 and the firstdiffusers 12 are located, and the second chamber 2 is delimited by thecommon wall 14, the side outer wall 15, the second top wall 17, and thesecond bottom wall in which the second air outlet 11 and the seconddiffusers 13 are located, so that the first chamber 1 is surrounded bythe second chamber 2. Furthermore, the air inlet 3 is located in thecommon wall 14 and the pressurized air supply conduit 9 communicateswith the air inlet 3 of the first chamber 1 going through the secondchamber 2. The communication opening of the air passage regulatingdevice 7 is formed in a region of the common wall 14, preferablyopposite the air inlet 3.

FIG. 9 shows a dual plenum according to a fifth embodiment which differsfrom the fourth embodiment (FIGS. 7 and 8) in that the air inlet 3 islocated in the first top wall 16 instead of in the common wall 14, andthe pressurized air supply conduit 9 is directly connected to the airinlet 3.

FIG. 10 shows a dual plenum according to a sixth embodiment having avertical design in which the common wall 14 is a vertical partition wallwhich is connected inside of a vertical cylindrical or prismatic sideouter wall 15 a, 15 b, so that the first and second chambers 1, 2 arearranged side by side adjacent to each other. The first chamber 1 isdelimited by the common wall 14, a first portion of the side outer wall15 a, a first top wall 16, and a first bottom wall in which the firstair outlet 10 and the first diffusers 12 are located. The second chamber2 is delimited by the common wall 14, a second portion of the side outerwall 15 b, a second top wall 17 and a second bottom wall in which thesecond air outlet 11 and the second diffusers 13 are located. Surfaces16 and 17 are in general coplanar or can optionally be made of a singlesurface.

The air inlet 3 is located in the first portion of the side outer wall15 a and the pressurized air supply conduit 9 is connected to the airsupply source 8 and to the air inlet 3. Alternatively, the air inlet 3could be located in the first top wall 16 and the pressurized air supplyconduit 9 directly connected to the air inlet 3. The communicationopening of the air passage regulating device 7 is located in the commonwall 14. The first and second diffusers 12, 13 provide respective firstand second air passage areas S1, S2 and are configured to direct air inone and the same inclined downwards direction or in different directionstaking into account there are two different diffusers 12 and 13. Aircirculation is shown by arrows in FIG. 10.

FIG. 11 shows a dual plenum according to a seventh embodiment whichdiffers from the sixth embodiment (FIG. 10) in that the air inlet 3 islocated in the common wall 14 and the pressurized air supply conduit 9communicates with the air inlet 3 of the first chamber 1 going throughthe second chamber 2. Alternatively, the air inlet 3 could be located inthe first top wall 16. Air circulation is shown by arrows in FIG. 11.

FIGS. 12 and 13 show a dual plenum according to an eighth embodimentwhich differs from the first embodiment (FIGS. 1 to 4) in that the airpassage regulating device 7 comprises a one-way valve device 4associated to the communication opening. The communication opening islocated in a vertical flat section of the common wall 14. The one-wayvalve device 4 comprises a flexible sheet secured at an upper edgethereof to the common wall 14 over the communication opening. Theflexible sheet is configured to freely hang by gravity thereby blockingthe communication opening when a pressure below a specific thresholdexists in the first chamber 1 (FIG. 12), and to bend to open thecommunication opening to a greater or lesser degree in response to apressure above the specific threshold value exerted on the flexiblesheet from the first chamber 1 (FIG. 13) thereby allowing a given flowrate of pressurized air to be shunt from the first chamber 1 to thesecond chamber 2. Air circulation is shown by arrows in FIGS. 12 and 13.In an alternative embodiment the flexible sheet may be secured byattachment 18 at one side of the communication opening.

FIG. 14 shows a dual plenum according to a ninth embodiment whichdiffers from the fourth embodiment (FIG. 7) in that the communicationopening is located in any vertical section of the common wall 14 and inthat the one-way valve device 4 comprises a sheet connected by a hinge19 at an upper edge thereof to the common wall 14 over the communicationopening. The rigid sheet is biased to freely hang into a closed position(shown in solid lines in FIG. 14) blocking the communication opening bythe action of its own weight. The sheet has the capacity to pivot aboutthe hinge 19 to open the communication opening to a greater or lesserdegree (shown in dashed lines in FIG. 14) in response to a pressureabove a specific threshold value exerted on the sheet from the firstchamber 1 thereby allowing a given flow rate of pressurized air to beshunt from the first chamber 1 to the second chamber 2.

FIGS. 15 and 16 show a dual plenum according to a tenth embodiment whichdiffers from the eighth embodiment (FIGS. 12 and 13) in the firstinstance in that the first top wall 16 has a perimetral edge connectedto the side outer wall 15, the second top wall 17 has a perimetral edgeconnected to the common wall 14, and a section of the first chamber 1extends between the first top wall 16 and the second top wall 17 therebythe second top wall 17 is also a wall common to the first and secondchambers 1, 2 in addition to the common wall 14.

Secondly, this tenth embodiment differs from the eighth embodiment inthat the communication opening is located in the second top wall 17common to the first and second chambers 1, 2, and the one-way valvedevice 4 comprises a sheet connected by a hinge 19 at an edge thereof tothe common wall 14 adjacent to the communication opening. The sheet isbiased to a closed position (FIG. 15) blocking the communication openingby the action of an elastic element 20. The sheet has the capacity topivot about the hinge 19 to open the communication opening to a greateror lesser degree (FIG. 16) in response to a pressure above a specificthreshold value exerted on the sheet from the first chamber 1 therebyallowing a given flow rate of pressurized air to be shunt from the firstchamber 1 to the second chamber 2. Air circulation is shown by arrows inFIGS. 15 and 16.

The elastic element 20, which can be associated to the hinge 19 forexample, allows for the one-way valve device 4 to be located in ahorizontal wall such as the second top wall 17, and readily lets anaccurate calibration of the one-way valve device 4 to the specificpressure threshold value. Alternatively, the one-way valve device 4could be located in in any other wall common to the first and secondchambers 1, 2.

FIG. 17 shows a dual plenum according to an eleventh embodiment whichdiffers from the ninth embodiment (FIG. 14) in the first instance inthat the first top wall 16 has a perimetral edge connected to the commonwall 14, the second top wall 17 has a perimetral edge connected to theside outer wall 15, and a section of the second chamber 2 extendsbetween the first top wall 16 and the second top wall 17 thereby thefirst top wall 16 is also a wall common to the first and second chambers1, 2 in addition to the common wall 14.

Secondly, this eleventh embodiment differs from the ninth embodiment inthat the one-way valve device 4 is an automatically actuated mechanicalvalve device 21 having a movable part which partially opens, closes, orobstructs one or more orifices or conduits associated to thecommunication opening thereby allowing a given flow rate of pressurizedair to be shunt from the first chamber 1 to the second chamber 2. One ormore pressure sensors 22 are arranged in the first chamber 1 to sensepressure therein, and an electronic control device 23 operates themechanical valve device 21 in response to a signal representative of a apressure above a specific threshold value in the first chamber 1received from the one or more pressure sensors 22. In this eleventhembodiment, the communication opening and the associated mechanicalvalve device 21 are located in the first top wall 16, althoughalternatively they could be located in any other wall common to thefirst and second chambers 1, 2.

In any of the first to seventh embodiments described above (FIGS. 1-11),more than one air passage regulating device 7, each having one or morecommunication openings, could be placed in one or more of the wallscommon to the first and second chambers 1, 2. In any of the eighth toeleventh embodiments described above (FIGS. 12-17), more than oneone-way valve device 4, each associated to a communication opening,could be placed in one or more of the walls common to the first andsecond chambers 1, 2.

The scope of the invention is defined by the attached claims.

1. A dual plenum for air distribution comprising: a first chamber (1)and a second chamber (2) sharing at least one common wall (14) andfurther sharing an air outlet (10, 11) having diffusers (12, 13) in anair passage area (S1, S2) configured to direct air within an enclosurein general of a building. an air-feed device configured to selectivelyintroduce, through an air supply conduit (9), pressurized air from anair supply source (8) to the first chamber (1) or to both the firstchamber and the second chamber (2) in response to a supplied pressurizedair flow rate; wherein said first chamber (1) is connected to one firstair passage area (S1) of said air outlet (10), and said second chamber(2) is connected to a second air passage area (S2) of said air outlet(11), characterized in that the pressurized air supply conduit (9) isconnected only to the first chamber (1); the common wall (14), includesan air passage regulating device (7) configured to selectivelycommunicate the second chamber (2) to the first chamber (1) in responseto an air pressure level in the first chamber (1) caused by the suppliedpressurized air flow rate.
 2. The dual plenum according to claim 1,wherein the common wall including the air passage regulating device (7)is adjacent to a region of the first chamber (1) directly connected tothe first surface area (S1) without interposed constrictions.
 3. Thedual plenum according to claim 1, wherein the air passage regulatingdevice (7) comprises one or more communication openings in the commonwall (14), the one or more communication openings providing a third airpassage area (S3). The ratio of the third air passage area (S3) to thefirst air passage area (S1) being selected to allow a given flow rate ofpressurized air to be shunt from the first chamber (1) to the secondchamber (2) in response to the air pressure level in the first chamber(1).
 4. The dual plenum according to claim 1, wherein the air passageregulating device (7) comprises a one-way valve device (4) associated toa communication opening in the common wall (14), the one-way valvedevice (4) being configured to open in response to a pressure valueinside the first chamber (1) above a specific threshold value therebyallowing a given flow rate of pressurized air to be shunt from the firstchamber (1) to the second chamber (2).
 5. The dual plenum according toclaim 1, wherein: the common wall (14) is a vertical cylindrical orprismatic wall surrounded by a cylindrical or prismatic side outer wall(15) and the second chamber (2) is surrounded by the first chamber (1);the first chamber (1) is delimited by the common wall (14), the sideouter wall (15), a first top wall (16), and a first bottom wall in whichthe first air outlet (10) and the first diffusers (12) are located; thesecond chamber (2) is delimited by the common wall (14), a second topwall (17), and a second bottom wall in which the second air outlet (11)and the second diffusers (13) are located; and the air inlet (3) islocated in the side outer wall (15) or in the first top wall (16). 6.The dual plenum according to claim 3, wherein: the common wall (14) is avertical cylindrical or prismatic wall surrounded by a cylindrical orprismatic side outer wall (15) and the second chamber (2) is surroundedby the first chamber (1); the first chamber (1) is delimited by thecommon wall (14), the side outer wall (15), a first top wall (16), and afirst bottom wall in which the first air outlet (10) and the firstdiffusers (12) are located; the second chamber (2) is delimited by thecommon wall (14), a second top wall (17), and a second bottom wall inwhich the second air outlet (11) and the second diffusers (13) arelocated; and the air inlet (3) is located in the side outer wall (15) orin the first top wall (16).
 7. The dual plenum according to claim 4,wherein: the common wall (14) is a vertical cylindrical or prismaticwall surrounded by a cylindrical or prismatic side outer wall (15) andthe second chamber (2) is surrounded by the first chamber (1); the firstchamber (1) is delimited by the common wall (14), the side outer wall(15), a first top wall (16), and a first bottom wall in which the firstair outlet (10) and the first diffusers (12) are located; the secondchamber (2) is delimited by the common wall (14), a second top wall(17), and a second bottom wall in which the second air outlet (11) andthe second diffusers (13) are located; and the air inlet (3) is locatedin the side outer wall (15) or in the first top wall (16).
 8. The dualplenum according to claim 1, wherein: the common wall (14) is a verticalcylindrical or prismatic wall surrounded by a cylindrical or prismaticside outer wall (15) and the first chamber (1) is surrounded by thesecond chamber (2); the first chamber (1) is delimited by the commonwall (14), a first top wall (16), and a first bottom wall in which thefirst air outlet (10) and the first diffusers (12) are located; thesecond chamber (2) is delimited by the common wall (14), the side outerwall (15), a second top wall (17), and a second bottom wall in which thesecond air outlet (11) and the second diffusers (13) are located; andthe air inlet (3) is located in the common wall (14) and the pressurizedair supply conduit (9) communicates with the air inlet (3) of the firstchamber (1) going through the second chamber (2); or the air inlet (3)is located in the first top wall (16).
 9. The dual plenum according toclaim 3, wherein: the common wall (14) is a vertical cylindrical orprismatic wall surrounded by a cylindrical or prismatic side outer wall(15) and the first chamber (1) is surrounded by the second chamber (2);the first chamber (1) is delimited by the common wall (14), a first topwall (16), and a first bottom wall in which the first air outlet (10)and the first diffusers (12) are located; the second chamber (2) isdelimited by the common wall (14), the side outer wall (15), a secondtop wall (17), and a second bottom wall in which the second air outlet(11) and the second diffusers (13) are located; and the air inlet (3) islocated in the common wall (14) and the pressurized air supply conduit(9) communicates with the air inlet (3) of the first chamber (1) goingthrough the second chamber (2); or the air inlet (3) is located in thefirst top wall (16).
 10. The dual plenum according to claim 4, wherein:the common wall (14) is a vertical cylindrical or prismatic wallsurrounded by a cylindrical or prismatic side outer wall (15) and thefirst chamber (1) is surrounded by the second chamber (2); the firstchamber (1) is delimited by the common wall (14), a first top wall (16),and a first bottom wall in which the first air outlet (10) and the firstdiffusers (12) are located; the second chamber (2) is delimited by thecommon wall (14), the side outer wall (15), a second top wall (17), anda second bottom wall in which the second air outlet (11) and the seconddiffusers (13) are located; and the air inlet (3) is located in thecommon wall (14) and the pressurized air supply conduit (9) communicateswith the air inlet (3) of the first chamber (1) going through the secondchamber (2); or the air inlet (3) is located in the first top wall (16).11. The dual plenum according to claim 5, wherein: the first top wall(16) has a perimetral edge connected to the side outer wall (15) and aninner edge connected to the common wall (14), and the second top wall(17) has a perimetral edge connected to the common wall (14), or thefirst top wall (16) has a perimetral edge connected to the common wall(14), and the second top wall (17) has a perimetral edge connected tothe side outer wall (15) and an inner edge connected to the common wall(14).
 12. The dual plenum according to claim 8, wherein: the first topwall (16) has a perimetral edge connected to the side outer wall (15)and an inner edge connected to the common wall (14), and the second topwall (17) has a perimetral edge connected to the common wall (14), orthe first top wall (16) has a perimetral edge connected to the commonwall (14), and the second top wall (17) has a perimetral edge connectedto the side outer wall (15) and an inner edge connected to the commonwall (14).
 13. The dual plenum according to claim 5, wherein the firsttop wall (16) has a perimetral edge connected to the side outer wall(15), the second top wall (17) has a perimetral edge connected to thecommon wall (14), and a section of the first chamber (1) extends betweenthe first top wall (16) and the second top wall (17).
 14. The dualplenum according to claim 8, wherein the first top wall (16) has aperimetral edge connected to the common wall (14), the second top wall(17) has a perimetral edge connected to the side outer wall (15), and asection of the second chamber (2) extends between the first top wall(16) and the second top wall (17).
 15. The dual plenum according toclaim 5, wherein the one or more communication openings of the airpassage regulating device (7) are formed in a region of the common wall(14) facing a portion of the side outer wall (15) opposite the air inlet(3).
 16. The dual plenum according to claim 8, wherein the one or morecommunication openings of the air passage regulating device (7) areformed in a region of the common wall (14) opposite the air inlet (3).17. The dual plenum according to claim 1, wherein: the common wall (14)is a partition wall which is connected inside of a vertical cylindricalor prismatic side outer wall (15 a, 15 b) and the first and secondchambers (1, 2) are arranged adjacent side by side; the first chamber(1) is delimited by the common wall (14), a first portion of the sideouter wall (15 a), a first top wall (16), and a first bottom wall inwhich the first air outlet (10) and the first diffusers (12) arelocated; the second chamber (2) is delimited by the common wall (14), asecond portion of the side outer wall (15 b), a second top wall (17) anda second bottom wall in which the second air outlet (11) and the seconddiffusers (13) are located; and the air inlet (3) is located in thefirst portion of the side outer wall (15 a); or the air inlet (3) islocated in the first top wall (16); or the air inlet (3) is located inthe common wall (14) and the pressurized air supply conduit (9)communicates with the air inlet (3) of the first chamber (1) goingthrough the second chamber (2).
 18. The dual plenum according to claim3, wherein: the common wall (14) is a partition wall which is connectedinside of a vertical cylindrical or prismatic side outer wall (15 a, 15b) and the first and second chambers (1, 2) are arranged adjacent sideby side; the first chamber (1) is delimited by the common wall (14), afirst portion of the side outer wall (15 a), a first top wall (16), anda first bottom wall in which the first air outlet (10) and the firstdiffusers (12) are located; the second chamber (2) is delimited by thecommon wall (14), a second portion of the side outer wall (15 b), asecond top wall (17) and a second bottom wall in which the second airoutlet (11) and the second diffusers (13) are located; and the air inlet(3) is located in the first portion of the side outer wall (15 a); orthe air inlet (3) is located in the first top wall (16); or the airinlet (3) is located in the common wall (14) and the pressurized airsupply conduit (9) communicates with the air inlet (3) of the firstchamber (1) going through the second chamber (2).
 19. The dual plenumaccording to claim 4, wherein: the common wall (14) is a partition wallwhich is connected inside of a vertical cylindrical or prismatic sideouter wall (15 a, 15 b) and the first and second chambers (1, 2) arearranged adjacent side by side; the first chamber (1) is delimited bythe common wall (14), a first portion of the side outer wall (15 a), afirst top wall (16), and a first bottom wall in which the first airoutlet (10) and the first diffusers (12) are located; the second chamber(2) is delimited by the common wall (14), a second portion of the sideouter wall (15 b), a second top wall (17) and a second bottom wall inwhich the second air outlet (11) and the second diffusers (13) arelocated; and the air inlet (3) is located in the first portion of theside outer wall (15 a); or the air inlet (3) is located in the first topwall (16); or the air inlet (3) is located in the common wall (14) andthe pressurized air supply conduit (9) communicates with the air inlet(3) of the first chamber (1) going through the second chamber (2). 20.The mixed plenum according to claim 4, wherein the communication openingis located in a vertical flat section of the common wall (14), and theone-way valve device (4) comprises a sheet secured by an attachment orhinge (19) at an upper or side edge thereof to the common wall (14) overthe communication opening with the capacity to block the communicationopening by gravity and to bend to open the communication opening to agreater or lesser degree in response to a pressure exerted on theflexible sheet.
 21. The mixed plenum according to claim 4, wherein thecommunication opening is located in any wall common to the first andsecond chambers (1, 2), and the one-way valve device (4) comprises asheet connected by a hinge (19) at an edge thereof to the common wall(14) adjacent to the communication opening, the sheet being biased to aclosed position blocking the communication opening by the action of anelastic element (20), the sheet having the capacity to pivot to open thecommunication opening to a greater or lesser degree in response to apressure exerted on the sheet.
 22. The mixed plenum according to claim4, wherein the communication opening is located in a vertical section ofthe common wall (14), and the one-way valve device (4) comprises a sheetconnected by a hinge (19) at an upper edge thereof to the common wall(14) over the communication opening, the sheet being biased to a closedposition blocking the communication opening by the action of its ownweight, the sheet having the capacity to pivot to open the communicationopening to a greater or lesser degree in response to a pressure exertedon the sheet.
 23. The mixed plenum according to claim 4, wherein thecommunication opening is located in any wall common to the first andsecond chambers (1, 2), and the one-way valve device (4) is anautomatically actuated mechanical valve device (21) having a movablepart which partially opens, closes, or obstructs one or more orifices orconduits associated to the communication opening in cooperation with atleast pressure sensor (22) and an electronic control device (23).